I came across a sample file that I'm having trouble figuring out how it was encoded. According to the LAME tag, it's encoded with LAME v3.92 and while v3.92 doesn't actually store the preset used, according to the rest of the info in the LAME tag it appears to be encoded using --alt-preset standard (vbr_quality = 78; vbr_method = vbr-old / vbr-rh; noise_shaping = 2; stereo_mode = joint; ath_type = 4; lowpass = 19000). The problem is that the LAME tag also says that a minimum bitrate of 192kbps was specified, and yet the actual bitrates are distributed like this (which looks like normal --aps):

QUOTE

128 -> 4 160 -> 963 192 -> 2658 224 -> 817 256 -> 246 320 -> 65

I haven't been able to replicate how the LAME tag has minimum bitrate of 192 but 128 and 160 frames appear in the file. I've tried:--alt-preset standard -b 192--alt-preset 192--abr 192